\begin{{tabular}}{{l p{{2mm}} l l l}}
    \toprule
        &
        & (1)
        & (2)
        & (3)
    \\
        &
        & \multicolumn{{1}}{{l}}{{Complexity}}
        & \multicolumn{{1}}{{l}}{{Complexity}}
        & \multicolumn{{1}}{{l}}{{Complexity}}
    \\
    \cmidrule{{1-1}} \cmidrule{{3-5}}
        1[Low-spec]
        &
        & {low_0}
        & {low_1}
        & {low_2}
    \\
        &
        & ({se_low_0})
        & ({se_low_1})
        & ({se_low_2})
    \\
        1[Low-spec] $\times$ 1[Boom]
        &
        & {low_boom_0}
        & {low_boom_1}
        & {low_boom_2}
    \\
        &
        & ({se_low_boom_0})
        & ({se_low_boom_1})
        & ({se_low_boom_2})
    \\
        1[Mid-spec]
        &
        & {mid_0}
        & {mid_1}
        & {mid_2}
    \\
        &
        & ({se_mid_0})
        & ({se_mid_1})
        & ({se_mid_2})
    \\
        1[Mid-spec] $\times$ 1[Boom]
        &
        & {mid_boom_0}
        & {mid_boom_1}
        & {mid_boom_2}
    \\
        &
        & ({se_mid_boom_0})
        & ({se_mid_boom_1})
        & ({se_mid_boom_2})
    \\
        1[High-spec]
        &
        & {high_0}
        & {high_1}
        & {high_2}
    \\
        &
        & ({se_high_0})
        & ({se_high_1})
        & ({se_high_2})
    \\
        1[High-spec] $\times$ 1[Boom]
        &
        & {high_boom_0}
        & {high_boom_1}
        & {high_boom_2}
    \\
        &
        & ({se_high_boom_0})
        & ({se_high_boom_1})
        & ({se_high_boom_2})
    \\
   \midrule
   Project controls
        &
        & No
        & Yes
        & Yes
    \\
        Contract-type controls
        &
        & No
        & No
        & Yes
    \\
    \midrule
        N
        &
        & {n_0}
        & {n_1}
        & {n_2}
    \\
    \bottomrule
\end{{tabular}}